The present invention relates to a printer which has a platen for supporting a printing sheet and a carriage mounted with a print head adapted to move relatively to the platen for printing operation, and is adapted to be operated by electric power supplied from an external power source.
Printers of this type contain therein various complicated mechanisms and a number of components, such as a printing mechanism including a platen, carriage, etc., a control section for controlling the operation of the printing mechanism, a power supply section adapted to supply power from an external power source to the printing mechanism through the control section.
In assembling the printer, these mechanisms and components generally are mounted separately on, for example, the machine frame or chassis of the printer in succession. Thus, the assembly work is inefficient, and the mounting accuracy of the components is not high enough.
To cope with this, an improved method of assembly is proposed in which some of the mechanical components including the platen, print head, carriage, etc., are previously unitized, and the resultant unit structure is then mounted on the machine frame. However, this improvement cannot effect a satisfactory settlement yet, since the unitized components constitute only a very small part of the whole structure of the printer.
The aforesaid problems have an adverse influence on the efficiency of maintenance or inspection of various sections of the printer. For higher efficiency of the maintenance or inspection work, it is necessary that the mechanical sections be able to be each categorized as a single unit and be easy for operator access.
In the prior art printers, however, these points are not fully considered, and the mechanical sections have a sophisticated layout. Accordingly, it is hard to seize the arrangement of the individual mechanical sections, and the components or spots to be inspected may not be accessible unless a number of parts are disassembled or removed from the printer.
In connection with these problems, the power supply section generally is disposed inside the printer, e.g., in the rear portion of its inside space. Moreover, the power supply section is provided with a transformer, whereby power from an external high-voltage power source is converted into a necessary low-voltage power for the drive of the printer. When using the printer in a district of a different external supply voltage, however, it is necessary that the internally arranged power supply section be removed, or that the transformer be taken out of the casing of the power supply section to be replaced with an alternative one, inevitably requiring a rearrangement of wiring. Since the power supply section is located within the printer, its removal or the replacement of the transformer is very troublesome, necessitating an improvement.